The ever expanding use of semiconductor light emitting devices has produced a highly competitive market for these devices in a variety of configurations. In this market, performance and price are often significant for providing product distinction among vendors.
To achieve high light output intensity, an array of light emitting devices is typically used. Such arrays may be configured in a variety of circuit configurations. Series configurations may be used to provide a uniform current to each device, whereas parallel configurations may be used to allow the use of a low voltage supply. Series-parallel configurations may be used to achieve a particular combination of performance features.
Conventionally, a patterned conductive layer is formed on a substrate, such as a printed circuit board with a conductive layer that is etched to create the desired interconnections between the devices that will be mounted on the board. Flexible substrates may also be used, with the desired interconnections formed by etching or by printing conductive ink on the substrate. Other forms of substrates and patterned conductive interconnections may also be used.
Each different circuit configuration requires a different pattern of conductive traces (different ‘layouts’). This requires the creation of different layout masks for etching, or different print patterns for printing each different pattern. In addition to the added design costs for developing each different pattern, the variety of patterns often precludes the economies of scale available for large production quantities.